1. Technical Field of the Invention
The present invention relates to the field of manual control of a cursor/pointer on a display screen, and more particularly, to the control of a cursor/pointer utilizing a solid state capacitive sensor array.
2. Description of Related Art
One of the most widely used types of user interfaces with a computer or television display screen is a screen cursor/pointer. The screen cursor/pointer normally comprises an arrow or some other type of visual indicating device whose position a user may control using a mouse, roller ball, joystick, or other type of apparatus for manipulating the position of the cursor/pointer on a display screen in order to select and manipulate information represented on the display screen.
The prior art provides several general types of devices for achieving screen cursor/pointer movement control. In a first type of device, of which a mouse is an example, continuous manual movement of the mouse across a generally horizontal surface (such as a mousepad) is required in order to produce a continuous corresponding direction of movement of the cursor/pointer across the display screen. This cursor/pointer movement stops when movement of the mouse stops. When the cursor/pointer must be moved a large screen distance, it is normally necessary to lift the mouse off the surface of the associated mouse pad, and then retrace the mouse over the horizontal surface one or more times.
A second type of device, of which a joystick is an example, responds to positioning of the joystick in an off center position. As long as the joystick is manually held in an off center position, the cursor/pointer continuously moves in a corresponding direction across the screen. In order to stop movement of the cursor/pointer, the joystick is returned to its center or neutral position.
Another implementation disclosed in U.S. patent application Ser. No. 09/012,065, entitled “Touchpad Providing Screen Cursor/Pointer Movement Control”, filed Jan. 22, 1998 , which is incorporated herein by reference, utilizes a plurality of capacitance sensing cells arranged in a row/column array to cooperate with a fingertip and produce an output signal that controls the movement of a cursor/pointer across a display screen. The output of each individual sensing cell is connected to a corresponding individual node of a resistor array that has end nodes arranged in a similar row/column array. A central output of the resistor node array configuration provides an output signal for controlling of cursor/pointer movement. A central output of the resistor nodes array configuration provides an output signal for control of cursor/pointer movement.
In the case of the first two implementations, large, bulky pieces of attached hardware are causing additional cost and size restrictions which may not be desirable in smaller computing applications, such as lap top computers. The implementation disclosed in U.S. patent application Ser. No. 09/012,065 suffers from the disadvantage that the silicon area on which the finger is placed, must be equal in size to the area of the finger. This can require quite a large silicon area and may be quite costly. Thus, a more size and cost efficient solution is desired.